This article contends that environmental organisations vary in type, scale and purpose in ways that help stewards self-sort into the opportunities that align with their individual motivations and environmental concerns. To explore these potential links between personal motivations and environmental organisational attributes, we rely on descriptive and inferential statistics from surveys of two partner environmental organisations: one local scale community based-organisation and one a broader scale environmental non-profit organisation, both located in Central Texas, USA. These partners were selected based on (...) their compatible pro-environmental missions but disparate spatial scales of operation. The survey results (n=377) revealed meaningful between-organisation differences in volunteer environmental stewards, which raise the possibility of a ‘First Law of Environmental Stewardship’ whereby all stewards are related (by their values), but stewards in the same organisation are more related than stewards in different organisations. These findings expose some of the nuances of environmental volunteerism by highlighting connections between personal motivations, geographic scale, and organisation type. (shrink)